The primary function of modern operating systems is to allow multiple programs to run, without interfering with each other, even if they try too. This means that each program can only read its own limited amount of memory and only gets to use the processor for a limited time, before another program gets a turn. Windows did not start using those features until Windows NT, which XP is based off of. Through Windows 98, any program could do whatever it wanted, and that hardware sat idle. Windows versions up to 98 were more like a library of features that a program could use, to display a user interface and talk to hardware peripherals.
There's special hardware in a processor, for the operating system to limit each programs access to memory and processing time, which Windows 9x leaves unused. This means that the Windows 9x Subsystem for Linux can say "look at me i'm the operating system now" and take over that hardware to run a modern operating system.
There's special hardware in a processor, for the operating system to limit each programs access to memory and processing time, which Windows 9x leaves unused. This means that the Windows 9x Subsystem for Linux can say "look at me i'm the operating system now" and take over that hardware to run a modern operating system.